The term streaming media describes the playback of media on a playback device, where the media is stored on a server and continuously sent to the playback device over a network during playback. Typically, the playback device stores a sufficient quantity of media in a buffer at any given time during playback to prevent disruption of playback due to the playback device completing playback of all the buffered media prior to receipt of the next portion of media. Adaptive bitrate streaming, or adaptive streaming, involves detecting the present streaming conditions (e.g. the user's network bandwidth and CPU capacity) in real time and adjusting the quality of the streamed media accordingly. Streaming video over the Internet has become a phenomenon in modern times. Many popular websites, such as YouTube, a service of Google, Inc. of Mountain View, Calif., and WatchESPN, a service of ESPN of Bristol, Conn., utilize streaming video in order to provide video and television programming to consumers via the Internet.
Scalable Video Coding (SVC) is an extension of the H.264/MPEG-4 AVC video compression standard, which is specified by the ITU-T H.264 standard by the International Telecommunication Union Telecommunication Standardization Sector of Geneva, Switzerland. SVC enables the encoding of a video bitstream that additionally contains one or more sub-bitstreams. The sub-bitstreams are derived from the video bitstream by dropping packets of data from the video bitstream, resulting in a sub-bitstream of lower quality and lower bandwidth than the original video bitstream. SVC supports three forms of scaling a video bitstream into sub-bitstreams: temporal scaling, spatial scaling, and quality scaling. Each of these scaling techniques can be used individually or combined depending on the specific video system.
In adaptive streaming systems, the source media is typically stored on a media server as a top level index file pointing to a number of alternate streams that contain the actual video and audio data. Each stream is typically stored in one or more container files. Different adaptive streaming solutions typically utilize different index and media containers. The Matroska container is a media container developed as an open standard project by the Matroska non-profit organization of Aussonne, France. The Matroska container is based upon Extensible Binary Meta Language (EBML), which is a binary derivative of the Extensible Markup Language (XML). Decoding of the Matroska container is supported by many consumer electronics (CE) devices. The DivX Plus file format developed by DivX, LLC of San Diego, Calif. utilizes an extension of the Matroska container format, including elements that are not specified within the Matroska format.